DE2048909C3 - Automatic, speed-dependent switching device for gear transmissions - Google Patents

Description

device operated. <8 & years since the beginning of the coupling and switching process

anüc & ea

From DT-PS 572 002 a device according to the starting point of the invention is known, which is used to automatically adjust the translation of a motor vehicle and has a centrifugal governor, which is driven by the motor shaft with constant translation and adjusted according to a predetermined-ItetrDreh Speed "in the control valve that "one connected to the change gear hydraulic ¥ _Ke?) jStellVorrichtung not just constantly adjusted with double-acting piston & 8IE the top gear ratio without nbetätigung a clutch, diving after reaching a location for quick

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included. This contains a pump that is driven by the output valve and feeds pressure into a cylinder with a simple acting valve. The piston rod actuates a cam mechanism with two different cam surfaces, one of which controls the actual gear shift and the other controls a selector valve. A throttle valve goes from the cylinder inlet line

» Containing branch off. which is connected to the space of the cylinder behind the piston and also to the pump inlet. In addition, a number of lines corresponding to the switching stages, which contain throttling points and connect the cylinder chamber with the return line to the pump inlet side, open into the cylinder at points which are in the initial position of the piston between the piston back and the connection for the branch just mentioned. Such a throttled discharge causes, as soon as its connection point has been passed by the piston at increasing speed, that the piston first stops in the newly acquired position until the gear output shaft exceeds the speed of the stage in question considerably and thus the output pressure of the pump is increased accordingly. A mechanical device or pressure, which depends on the position of the throttle valve, also acts on the piston.

With common speed gearboxes it is required, a servo device to select the gear mesh to be provided for each of the fork or claw elements, see e.g. B. DTPS 685 707. As there it is not possible to operate these servo devices at the same time, not even if clutches or Braking devices are mainly provided with planetary gear devices, must at least two claw elements are controlled separately. This results in the complicated structure the known devices and the disadvantages associated with them.

The invention aims to provide an extremely reliable and simple speed changing device. According to the solution according to the invention, several switching elements can be performed with reduced torque of the cam, a single feedback circuit being sufficient for the automatic speed change processes
Advantageous refinements of the invention are specified in the subclaims.

From DT-AS 1 189 866 a device for shifting motor vehicle change gears is known, in which the individual gear shift elements have pins in curved slots one in both directions step-by-step rotatable cam are actuated, which at the same time forms a stepping wheel and therefore on Circumference for both directions of rotation with one notch group each is provided. For immediate use

file on stiff width one in both st & wenkbferer S & Wiebei arranged the aJwj2 »p'i ^ ali {we ^ KifengHff in beT ^ e Ra-

ΐπ a his * two SöiwenkVich obligations is betaSgbar The cam JSF continue as Füfirongsorgan with AusnehmungwKaid a stop is provided, cooperating with locking devices, which are by particular, the individual loading ίο ¹ twebszustSjiden associated switch operable and so in terms of a feedback to the Signalgebüng work, but in several circles. "

Preferred embodiments of the invention are explained and illustrated by way of example

F i g. t a longitudinal section through em gearbox In part of a switching device according to the invention,

FIG. 2 shows a section along the line AA ¹ of FIG. 1 to illustrate a curve arrangement,

^! 3 shows a simplified representation of a switching device according to the invention and

F i g. 4 and 5 of FIG. 2 similar representations to illustrate modified embodiments of the control cams.

F i g. 1 illustrates a change speed transmission with synchronous engagement, which is operated via a shifting device according to FIG Invention can be actuated, the transmission has an input shaft 10, an output shaft 1! and a friction clutch unit 12.

On the input shaft 10 there is an input gear 18 which is a counter or countershaft · input gear 19 and thus a countershaft 20 drives on which the gears 21, 25 and 30 are also arranged, of which the gear 21 with the gear 17.25 with 24 and 30 combs with 29

A bushing 13 located on the output side looks with its bore in spline teeth with the output shaft U and pushes to the right when it moves a first inner synchronization ring 15 along the pin 14 against an outer ring 16 so that the Gear 17 is synchronized with the output shaft U and is in spline connection with the bushing 13 occurs.

When the bushing 13 is moved to the left, a second inner synchronization ring 22 is positioned along the Pin 14 pressed against an outer ring 23. Thereby, the second gear 24 and the output shaft 11 synchronized.

Furthermore, a bushing 26 is provided for a higher speed range, the bore of which in Splined connection with the output shaft U is and a third synchronization ring 28 along a wedge 27 to the right in pressure contact with a third gear 29 or a synchronization ring 31 for the maximum speed to the left moved in pressure contact with the input gear 18.

In particular with reference to FIG. 3, the switching device for a transmission according to F i _b . 1 explained. The switching device has an oil container 32, and the liquid contained therein is fed by means of the pump 33 through a line 34 to an opening 36 in a control valve 35. The control valve 35 has a valve piston 37 and a sliding plug 38 on the side. A spring 39 is arranged between these parts. A spring 40 lies between the left end of the piston 37 and the left end

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The control valve 35 is also with 42/43, • | £, 45 !, 46 and 4f ejected by valve 37 shows a paragraph 48 for the control gate opening43, just paragraph 49 for controlling the opening 36 "and a paragraph 50 for controlling the opening 46 , a pressure regulator 51 provides for the generation of a hydraulic pressure corresponding to the revolutions represent 'wheel axle, the hydraulic pressure generated by the pump 33 is supplied to the pressure regulator 51 via a line 52, goes from which the pressure via a line 53 to the port 42

Excess fluid that is not needed for lines 34 and 52 goes via line 54 to a check ball valve 56, which through a spring 55 is secured and from which a line 57 goes back to the tank by means of fluid pressure in the lines 34 and 52 is therefore constant The pressure occurring at the opening 44 goes via a line 58 to the upshift chamber 60 of a servomotor 59. The pressure at the opening 45 goes via a Line 61 to the downshift chamber 62. The cam disk 41 has a bore 63 which has rectangular extensions into which a pin 65 engages is arranged on a shaft 64. The cam is therefore fixed on the shaft 64 and rotatable together with it. The shaft 64 is rotatable because it The cam disk 41 is mounted between the housing of the servomotor 59 and a housing part 59 ′ covered A rotary piston 66 is attached to the shaft 64 and rotates in the servomotor 59. On the outer A sealing element 67 is arranged at the end of the rotary piston 66 and is connected to the inner surface of the servomotor 59 seals. In the cam disk 41, cam slots 68 and 69 are formed independently of one another and opposite one another. Pins 70 and 71 engage the Slots 68 and 69 eia At the lower ends of the pins 70 and 7t, the claw elements 72 and 73 are attached, which serve to the socket 26 for the upper Speed range or the socket 13 for the lower speed range to the left and right to move. In the servomotor 59, a separating member 74 is arranged with a sealing element 75 against the shaft 64 is sealed

The operation of the switching device is explained below.

The oil in the tank 32 is fed by the pump 33 and via the line 34 to the opening 36 of the control valve 35. To start a motor vehicle, the shift lever for the change gear is moved into the first gear position. This movement of the shift lever is indicated by the dash-dotted arrow line B. The control valve 35 is operated so that the change gear is set to first gear. With an increase in the number of revolutions and with a correspondingly increased pressure of the pressure regulator 51, the pressure of the opening 42 is fed through the line 53 /. As a result, the valve piston 37 with reference to FIG. 3 shifted to the right, so that the opening 36 closed by the shoulder 49 is opened. The opening 36 thereby comes into connection with the opening 44.

The pressure medium, which is supplied by the pump 33, is thus introduced into the upshift chamber 60 of the servomotor 59 in order to move the piston 66. The shaft 64 is thereby, see FIG. 3, rotated clockwise together with the rotary piston 66.

At the same time, the cam 41 attached to the shaft 64 is also rotated clockwise In doing so, the pins 70 and 71, which engage in the curved slots 68 and ά), along these slots Moved to redrts and to the left, in order to correspondingly 'occupy' the claws with pins 70 and 71 are connected., The sockets 26 moves for the higher and 13 for the lower speed range for the shifting process,,

When the cam disk 41 rotates in a clockwise direction, the cam surface 4la is moved in the same direction, thereby causing the plug 38 is pushed to the left as the diameter of the cam rim 41a gradually increases. The valve 37 is pushed back into the drawing control by the spring 39, the opening 36 being closed by the shoulder 49. This turns the pressure feed to the Upshift chamber 60 ended and the pressure piston 66 and the claw members 72 and 73 held in the specific positions. The conditions for the speed change process are thus maintained in accordance with the number of revolutions.

When the number of revolutions decreases and the regulator pressure of the pressure regulator 51 falls, the Valve piston 37 is moved to the left, whereby the shoulder 49 is caused to release the opening 36, which is shown in FIG Communication with the opening 43 is brought. In order to the pressure of the downshift chamber 62 is supplied via the line 61. The piston 66 is in communication with the shaft 64 counterclockwise moved The cam 41 is rotated in the same direction and the pins 70 and 71 and that of these dependent claws 72 and 73 are moved in such a way that the conditions for the above-described speed changeover process are canceled. This creates a new one, the number of Revolutions corresponding switching process enables

The control valve piston 37 is simultaneously moved into the in

The position shown in the drawing is reset by the movement of the cam surface 41a. Since the opening 36 is closed by the shoulder 49, retained the claws 72 and 73 the position in .which they have been moved, and thus keep the condition for the Shifting process upright In this case, the shifting process can depend on the machine output can be performed by controlling the regulator pressure by the machine power.

ίο In the present embodiment, the works Servomotor 59 with a rotary piston. However, it can also be a cylinder with a linearly movable piston. In addition, in the case of a semi-automatic device, the arrangement can be chosen such that

is the shift lever "ft" with the control valve piston 37 in by the dash-dotted line in FIG. 3 is connected to the control valve piston is then moved without introducing regulator pressure from the pressure regulator.

ίο In the F i g. 4 and S are cam slots 169 and 269, respectively one of the cam slots 68 and 69 shown in FIG. 2 have a different form, in F i g. 2 are the Curved slots 68 and 69 designed so that the two slots are opposite each other independently.

In Fig. 4 a single cam slot 169 is provided, the ends of which do not meet.

In FIG. 5, the only cam slot 269 does not have any free end sections, but forms a closed shape. With regard to the way of working and the techni However, there are no fundamental effects differences between the slots of FIG. 2 and those according to FIG. 4 and 5, with the exception that by using a single cam slot as shown in FIG. 4 and 5, the angle of inclination of the cam surface can turn reduced. This ensures reliable control with less torque It is also not necessary for the cam to have a large diameter

For this purpose 2 sheets of drawings

5 ι. ? f "^ - ^ v

Claims (7)

Schakeinrid ^ iem tydrauJtit dasd «it mm or a signal windness emßr device ebb of the servomotor which in, Wirfcvererset / and further away cine the antithet" pretending Vorv-isC ^ a by gckenn- ".with Äciii piston (66} of the" * "'* ^ Jp9) directly connected to a cam disc (41) provides the switching claws (70 to 73) indirectly and depending on their rotational position on the piston (37) of the control valve acts opposite to the signal transmitter (51) 2. Switching device according to claim 1, characterized in that the servomotor (59) has a The rotary piston (66) has its shaft (64) firmly connected to the axis (63) of the cam disk (41) is. 3. Switching device according to claim I or 2, characterized in that a plurality of pins (70, 71) engage a cam slot (169; 269) of the cam disc (41) 4. Switching device according to claim 3, characterized in that the cam slot (269) forms a closed shape. 5. Switching device according to claim I or 2, characterized in that the cam disc (41) has two opposite Äurvenschlitze (68, 69) in each of which a pin (70, 71) engages. 6. Switching device according to one of claims 1 to 5, characterized by one on the cam (41) formed cam surface (4Ie) which is in contact with a slidably arranged The stopper (38) is on which the piston (37) of the control valve (35) is supported via a spring. 7. Switching device according to claim 6, characterized in that the one facing away from the plug (38) End (48) of the control valve piston (37) in a chamber which is at the outlet of one of an operating speed dependent pressure regulator (51) is connected. ... valve from rotatable and ver are. & Perne * is out
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